/*
 * (C) Copyright 2002
 * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
 *
 * Influenced by code from:
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */
#if 0
#include <linux/kmod.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/kernel.h>		/* printk()				*/
#include <linux/fs.h>			/* everything...		*/
#include <linux/errno.h>		/* error codes			*/
#include <linux/types.h>		/* size_t				*/
#include <linux/poll.h>
#include <asm/uaccess.h>		/* copy_from/to_user 	*/
#include <asm/io.h>
#include <linux/delay.h>
#include <linux/cdev.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/gpio.h>

#include <mach/regs-clock.h>
#include <mach/regs-gpio.h>

#include <mach/gpio-bank.h>
#include <mach/gpio.h>

#include <plat/gpio-cfg.h>

#endif
#include "ioctl.h"
#include "iodev.h"
#include "syscfg.h"
#include "regs.h"

#include "soft_spi.h"

#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
 
#define container_of(ptr, type, member) ({			\
	const typeof(((type *)0)->member) * __mptr = (ptr);	\
	(type *)((char *)__mptr - offsetof(type, member)); })

#if 1
#define RFID_SPI_CS		(76)
#define RFID_SPI_SCL		(75)
#define RFID_SPI_OUT	(87)
//define RFID_SPI_OUT	(74)

#define RFID_SPI_IN		(73)
#else
#define RFID_SPI_CS		(82)
#define RFID_SPI_SCL		(80)
//#define RFID_SPI_OUT	(87)
#define RFID_SPI_OUT	(79)

#define RFID_SPI_IN		(78)

#endif
/*-----------------------------------------------------------------------
 * Definitions
 */

#ifdef DEBUG_SPI
#define PRINTD(fmt,args...)	printf (fmt ,##args)
#else
#define PRINTD(fmt,args...)
#endif


#define SPI_SCL(x)		gpio_output(RFID_SPI_SCL, ( x))
#define SPI_DELAY	udelay(1)


struct soft_spi_slave {
	struct spi_slave slave;
	unsigned int mode;
};

static inline struct soft_spi_slave *to_soft_spi(struct spi_slave *slave)
{ 
	return container_of(slave, struct soft_spi_slave, slave);
}

char SPI_READ()
{
	//gpio_set_input(RFID_SPI_IN, 0);
	return gpio_input(RFID_SPI_IN);
	//gpio_direction_input(S5PV210_GPB(3));

	//return gpio_get_value(S5PV210_GPB(3));
}


void SPI_SDA(int x)
{
	//gpio_set_output(RFID_SPI_OUT, 0);
	if (x)
		gpio_output(RFID_SPI_OUT, 1);
	else
		gpio_output(RFID_SPI_OUT, 0);
	#if 0
	gpio_direction_output(S5PV210_GPB(3), 1); 
	if(x)
		gpio_set_value(S5PV210_GPB(3), 1);
	else
		gpio_set_value(S5PV210_GPB(3), 0);
	#endif
}


void spi_cs_activate(struct spi_slave *slave)
{
	gpio_output(RFID_SPI_CS, 0); 
}


void spi_cs_deactivate(struct spi_slave *slave)
{
	gpio_output(RFID_SPI_CS, 1); 
}


/*=====================================================================*/
/*                         Public Functions                            */
/*=====================================================================*/

/*-----------------------------------------------------------------------
 * Initialization
 */
void soft_spi_init (void)
{
#if 1
	 SYSCFG->PIN_MUXING0 |=GPIO76_EN | GPIO73_74_75_EN;
#else
	SYSCFG->PIN_MUXING0 |=GPIO78_79_80_EN;
	SYSCFG->PIN_MUXING1 |= GPIO82_EN;
#endif
	gpio_set_output(RFID_SPI_CS, 0);
	gpio_set_output(RFID_SPI_SCL, 0);
	gpio_set_output(RFID_SPI_OUT, 0);
	gpio_set_input(RFID_SPI_IN, 0);
}

int  spi_cs_is_valid(unsigned int bus, unsigned int cs)                           
{
	return 1;
}
struct soft_spi_slave rspi;

struct spi_slave *soft_spi_setup_slave(unsigned int bus, unsigned int cs,
		unsigned int max_hz, unsigned int mode)
{
	struct soft_spi_slave *ss = &rspi;

	if (!spi_cs_is_valid(bus, cs))
		return NULL; 

	ss->slave.bus = bus;
	ss->slave.cs = cs;
	ss->mode = mode;

	/* TODO: Use max_hz to limit the SCK rate */

	return &ss->slave;
}


void spi_free_slave(struct spi_slave *slave)
{
	struct soft_spi_slave *ss = to_soft_spi(slave);

	//kfree(ss);
}

int spi_claim_bus(struct spi_slave *slave)
{
#ifdef CONFIG_SYS_IMMR
	volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
#endif
	struct soft_spi_slave *ss = to_soft_spi(slave);
//	printk("%s:%d\n",__FUNCTION__,__LINE__);

	/*
	 * Make sure the SPI clock is in idle state as defined for
	 * this slave.
	 */
	if (ss->mode & SPI_CPOL)
		SPI_SCL(1);
	else
		SPI_SCL(0);

	return 0;
}

void spi_release_bus(struct spi_slave *slave)
{
	/* Nothing to do */
}



/*-----------------------------------------------------------------------
 * SPI transfer
 *
 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
 * "bitlen" bits in the SPI MISO port.  That's just the way SPI works.
 *
 * The source of the outgoing bits is the "dout" parameter and the
 * destination of the input bits is the "din" parameter.  Note that "dout"
 * and "din" can point to the same memory location, in which case the
 * input data overwrites the output data (since both are buffered by
 * temporary variables, this is OK).
 */
int  soft_spi_xfer(struct spi_slave *slave, unsigned int bitlen,
		const void *dout, void *din, unsigned long flags)
{
#ifdef CONFIG_SYS_IMMR
	volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
#endif
	struct soft_spi_slave *ss = to_soft_spi(slave);
	unsigned char		tmpdin  = 0;
	unsigned char		tmpdout = 0;
	const uint8_t	*txd = dout;
	
	uint8_t *rxd = din;
	int		cpol = ss->mode & SPI_CPOL;
	int		cpha = ss->mode & SPI_CPHA;
	unsigned int	j;

	if (flags & SPI_XFER_BEGIN){
	        	spi_cs_activate(slave);
	}
	for(j = 0; j < bitlen; j++) {
		/*
		 * Check if it is time to work on a new byte.
		 */
		if((j % 8) == 0) {
			if (dout) {
				tmpdout = *txd++;
			}
			if (din) {
				if(j != 0) {
					*rxd++ = tmpdin;
				}
				tmpdin  = 0;
			}				
		}
		if (!cpha)
			SPI_SCL(!cpol);
		if(dout) {
			SPI_SDA(tmpdout & 0x80);
		}
		SPI_DELAY;
	
		if (cpha)
			SPI_SCL(!cpol);
		else
			SPI_SCL(cpol);
		if (din) {
			tmpdin	<<= 1;		
			tmpdin	|= SPI_READ();
		}
		if (dout) {
			tmpdout <<= 1;
		}
		SPI_DELAY;
		if (cpha)
			SPI_SCL(cpol);
	}


	/*
	 * If the number of bits isn't a multiple of 8, shift the last
	 * bits over to left-justify them.  Then store the last byte
	 * read in.
	 */
	 if (din) { 
			if((bitlen % 8) != 0)
			tmpdin <<= 8 - (bitlen % 8);

			*rxd++ = tmpdin;
	 	}

	if (flags & SPI_XFER_END)
		spi_cs_deactivate(slave);
	return(0);
}

